[address-policy-wg] IXP pool lower boundary of assignments

Tore Anderson wrote on 08/11/2022 14:18:
> Apart from the BGP session itself (which supports multi-AF), the
> addresses are just needed for resolution of the next-hop layer-2
> address. There's no real reason that address needs to be IPv4 and
> resolved via ARP, it can be resolved just as well with IPv6 ND, as I
> understand it.
> 
> For example, on Linux, you can program the FIB in this way:
> 
> $ ip route add 192.0.2.0/24 via inet6 fe80::1 dev eth0
> 
> The 'eth0' interface does not need any IPv4 addresses assigned.

Right, ipv4 forwarding using ipv6 next hop resolution.  Wow, that's ugly 
and likely to introduce an entirely new class of low-level forwarding bugs.

> Obviously the major router vendors need to build in corresponding
> capability in their BGP software for IPv6-only IX-es to be a realistic
> proposition. I have no idea if they have.

In fairness, this goes well beyond updating a set of capabilities in 
vendor BGP stacks.

Nick